DAStatusChoice Enumeration

Status is a combination of QualityChoice and Substatus. Which Substatus values can be used depend on QualityChoice.

Syntax

Visual Basic
C#
C++/CLI

'Declaration
 
<CLSCompliantAttribute(True)>
<ComVisibleAttribute(True)>
<DisplayName2Attribute("OPC-DA Status Choice")>
<GuidAttribute("A9388FAB-303E-4A80-AF81-CD0068909655")>
Public Enum DAStatusChoice 
   Inherits System.Enum
   Implements System.IComparable, System.IConvertible, System.IFormattable

'Usage
 
Dim instance As DAStatusChoice

[CLSCompliant(true)]
[ComVisible(true)]
[DisplayName2("OPC-DA Status Choice")]
[Guid("A9388FAB-303E-4A80-AF81-CD0068909655")]
public enum DAStatusChoice : System.Enum, System.IComparable, System.IConvertible, System.IFormattable

[CLSCompliant(true)]
[ComVisible(true)]
[DisplayName2("OPC-DA Status Choice")]
[Guid("A9388FAB-303E-4A80-AF81-CD0068909655")]
public enum class DAStatusChoice : public System.Enum, System.IComparable, System.IConvertible, System.IFormattable

Members

Member	Value	Description
BadNonspecific	0	Non-specific. Substatus for BAD Quality: The value is bad but no specific reason is known. Remarks: Corresponds to OPC_QUALITY_BAD in the OPC specification.
CommFailure	6	Comm Failure. Substatus for BAD Quality: Communications have failed. There is no last known value is available. Remarks: Corresponds to OPC_QUALITY_COMM_FAILURE in the OPC specification.
ConfigError	1	Configuration Error. Substatus for BAD Quality: There is some server specific problem with the configuration. For example the item in question has been deleted from the configuration. Remarks: Corresponds to OPC_QUALITY_CONFIG_ERROR in the OPC specification.
DeviceFailure	3	Device Failure. Substatus for BAD Quality: A device failure has been detected. Remarks: Corresponds to OPC_QUALITY_DEVICE_FAILURE in the OPC specification.
EguExceeded	21	Engineering Units Exceeded. Substatus for UNCERTAIN Quality: The returned value is outside the limits defined for this parameter. Remark: In this case (per the Fieldbus Specification) the ‘Limits’ field indicates which limit has been exceeded but does NOT necessarily imply that the value cannot move farther out of range. Remarks: Corresponds to OPC_QUALITY_EGU_EXCEEDED in the OPC specification.
GoodNonspecific	48	Non-specific. Substatus for GOOD Quality: The value is good. There are no special conditions. Remarks: Corresponds to OPC_QUALITY_GOOD in the OPC specification.
LastKnown	5	Last Known Value. Substatus for BAD Quality: Communications have failed. However, the last known value is available. Remark: The ‘age’ of the value may be determined from the TIMESTAMP in the OPCITEMSTATE. Remarks: Corresponds to OPC_QUALITY_LAST_KNOWN in the OPC specification.
LastUsable	17	Last Usable Value. Substatus for UNCERTAIN Quality: Whatever was writing this value has stopped doing so. The returned value should be regarded as ‘stale’. Remark: This differs from a BAD value with Substatus 5 (Last Known Value). That status is associated specifically with a detectable communications error on a ‘fetched’ value. This error is associated with the failure of some external source to ‘put’ something into the value within an acceptable period of time. Remark: The ‘age’ of the value can be determined from the TIMESTAMP in OPCITEMSTATE. Remarks: Corresponds to OPC_QUALITY_LAST_USABLE in the OPC specification.
LocalOverride	54	Local Override. Substatus for GOOD Quality: The value has been Overridden. Typically this is means the input has been disconnected and a manually entered value has been ‘forced’. Remarks: Corresponds to OPC_QUALITY_LOCAL_OVERRIDE in the OPC specification.
NotConnected	2	Not Connected. Substatus for BAD Quality: The input is required to be logically connected to something but is not. This quality may reflect that no value is available at this time, for reasons like the value may have not been provided by the data source. Remarks: Corresponds to OPC_QUALITY_NOT_CONNECTED in the OPC specification.
OutOfService	7	Out of Service. Substatus for BAD Quality: The block is off scan or otherwise locked. This quality is also used when the active state of the item or the group containing the item is InActive. Remarks: Corresponds to OPC_QUALITY_OUT_OF_SERVICE in the OPC specification.
SensorCal	20	Sensor Not Accurate. Substatus for UNCERTAIN Quality: Either the value has ‘pegged’ at one of the sensor limits (in which case the limit field should be set to 1 or 2) or the sensor is otherwise known to be out of calibration via some form of internal diagnostics (in which case the limit field should be 0). Remarks: Corresponds to OPC_QUALITY_SENSOR_CAL in the OPC specification.
SensorFailure	4	Sensor Failure. Substatus for BAD Quality: A sensor failure had been detected (the ’Limits’ field can provide additional diagnostic information in some situations). Remarks: Corresponds to OPC_QUALITY_SENSOR_FAILURE in the OPC specification.
Subnormal	22	Sub-Normal. Substatus for UNCERTAIN Quality: The value is derived from multiple sources and has less than the required number of Good sources. Remarks: Corresponds to OPC_QUALITY_SUB_NORMAL in the OPC specification.
UncertainNonspecific	16	Non-specific. Substatus for UNCERTAIN Quality: There is no specific reason why the value is uncertain. Remarks: Corresponds to OPC_QUALITY_UNCERTAIN in the OPC specification.
WaitingForInitialData	8	Waiting for Initial Data. Substatus for BAD Quality: After Items are added to a group, it may take some time for the server to actually obtain values for these items. In such cases the client might perform a read (from cache), or establish a ConnectionPoint based subscription and/or execute a Refresh on such a subscription before the values are available. This substatus is only available from OPC DA 3.0 or newer servers. Remarks: Corresponds to OPC_QUALITY_WAITING_FOR_INITIAL_DATA in the OPC specification.

Inheritance Hierarchy

System.Object
   System.ValueType
      System.Enum
         OpcLabs.EasyOpc.DataAccess.DAStatusChoice

Requirements

Target Platforms: .NET Framework: Windows 10 (selected versions), Windows 11 (selected versions), Windows Server 2016, Windows Server 2022; .NET: Linux, macOS, Microsoft Windows

Reference

OpcLabs.EasyOpc.DataAccess Namespace

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